This invention deals generally with farm machinery and more specifically with a rotary raking machine modified into a windrow inverting machine.
Prior art farm machines include distinct raking machines and windrow inverter machines. Raking machines pick up scattered crop and deposit it into a windrow, a long continuous pile of crop, and, at a later time, an inverter machine is used to turn the windrow over so that the previous bottom portion of the windrow will dry.
The typical rotary rake machine is pulled behind a tractor and includes an assembly of extending arms formed into a pinwheel-like configuration which revolves in a horizontal plane. Each arm holds a group of wire tines that extend to the ground during part of the revolution of the arm assembly. In order to form the windrow, the tines are oriented vertically down with their ends at the ground to perform the raking operation. Then the tines are lifted up to stop the raking action and permit the formation of the windrow.
The typical rake machine divides the two positions of the tines into approximate halves of the circle of revolution of the arms. The tines are down and dropping or lifting as they pass the front of the machine, at the portion of the circle nearest to the tractor, and are then up as they pass the part of the circle most remote from the tractor. This motion rakes the crop from one side of the crop rake, toward the tractor, and then pushes it to one side of the path, forming the windrow.
Prior art inverters are completely different from rotary rake machines in that they essentially continuously pick up the windrow, reorient it, and lay it back down on the ground. U.S. Pat. No. 4,730,447 by Fisher uses tines in a belt arrangement to lift crop up a ramp onto a disc shaped platform with a circumferential wall. A pinwheel type assembly then drives vertically oriented tines that move the crop around the platform until it is moving in the same direction of travel as the tractor where it is pushed over a downward curved edge and onto the ground.
U.S. Pat. No. 5,251,431 by Shoop uses a cylindrical type rake rotating on a horizontal axis to invert the crop while throwing it onto a tilted rotating disc from where it is propelled to the ground while the crop is oriented approximately at a right angle to the direction of movement of the tractor.
U.S. Pat. No. 6,354,429 by Kuhlmann discloses an inverter that uses a sloped conveyor belt to lift the windrow onto a curved conveyor and a discharge conveyor to convey the crop from the opposite side of the curved conveyor to a location where it is dropped to the ground while the crop is moving in the same direction as the tractor.
The Fisher and Kuhlmann machines accomplish the inverting by discharging the crop while the crop itself is moving so as to produce a greater speed differential between the crop and the ground than between the inverting machine and the ground. This makes the speed of the crop relative to the ground greater than that of the platform from which it is dropped and causes the inverting of the crop.
However, the prior art windrow inverters have a significant problem. They all require a complex machine completely different from the crop rake or at least an additional apparatus used with a crop rake machine to accomplish the inverting. This adds a significant investment to any farm machine manufacturing operation.
It would be very beneficial to construct an inverting machine that was based upon a rotary rake machine, because the cost of manufacture would be significantly reduced.